Opponents of an opencast mining scheme in Merthyr Tydfil have staged a protest as the scheme was finally launched.
The Ffos-y-Fran site is near homes in Merthyr Tydfil
Ffos-y-Fran will become one of Europe's biggest opencast sites, mining 10m tonnes of coal over 17 years.
It has been the subject of years of campaigning, and Friends of the Earth Cymru said rules on how close opencast mines were to homes should be revised.
But the company involved said it was already bringing benefits to the area and would continue to do so.
The mine, which will reclaim derelict land, has been the subject of years of campaigning against it.
Friends of the Earth Cymru said that in Scotland mines must have a 500m (1,640ft) separation zone from homes. Ffos-y-Fran is just 36m (118ft) away from houses.
As the 1,000 acre site launched, local people said they would carry on campaigning as they were worried about the impact of noise and dust.
Terry Evans, who lives near the site, said: "The effect on my life would be devastating, obviously.
"It's up on the mountain looking down on me and I'm at the mercy of the weather because if the wind is blowing this way our estate will get the fall-out, and no matter what they do we will get the fall-out.
"They say it's not going to happen but it's already happened. They have had preparation works for the last couple of months on the roads a long way away.
"We have already had dust and pollution and the opencast hasn't started yet."
Opponents previously staged a protest march with a 'coffin'
Gordon James, director of Friends of the Earth Cymru, said: "It is accepted that opencast coal mining has harmful noise, pollution and landscape impacts on nearby communities and blights property prices.
"This is why Scotland has set a 500m separation zone to keep opencast away from homes.
"Yet at Ffos-y-Fran the development will be as close as 36m to the nearest homes. This injustice should not be allowed."
The launch signals an end to years of delays.
Miller Argent (South Wales) Ltd initially received planning permission following a public inquiry, only for that to be overruled by the High Court.
But the Welsh Assembly Government, which backed Ffos-y-Fran, won the right to appeal and a Court of Appeal judge allowed it to go ahead.
Steve Tillman, director of Miller Argent, said: "I think the benefits can be seen already.
"If you actually look at phases one and two of the East Merthyr Reclamation Scheme, the benefits are there and are demonstrable," he said.
"We're here to do and deliver the same again but over a larger area and the benefits will be there for the future generations."